Atomic Layer Deposition of Cerium Oxide for Potential Use in Solid Oxide Fuel Cells

Abstract

With the growing need for sustainable energy, solid oxide fuel cells are an attractive alternative for power generation since they are efficient and environmentally friendly. However, required high operating temperatures limit their widespread use. The two ways to reduce the operating temperature of solid oxide fuel cells is to decrease the thickness of the electrolyte and to use new materials that have lower ion resistivities. In this study, both methods were employed. Currently, yttrium stabilized zirconium is the material used in solid oxide fuel cells as the electrolyte, and in this study cerium oxide was examined to be a potential replacement. To decrease the thickness of the electrolyte, thin films production techniques can be used. One technique for making thin films is atomic layer deposition, also known as ALD, which uses alternating saturative surface reactions. ALD creates films that have good conformality, are pin-hole free, and thickness is easily controlled. In this study, the atomic layer deposition of cerium oxide was studied for potential use in solid oxide fuel cells as the electrolyte and anode. The optimum precursor temperature was found to be 130 °C and the water pulse length was found to be 55 ms. The ALD window, which is the temperature range of ideal ALD growth, was determined to be 210 to 280 °C, the surface was saturated when at least four plugs of precursor pulses were used in the procedure, and the growth was linear at 1.2 Å/cycle.